Methods for transferring a useful layer of silicon carbide to a receiving substrate are described. In an embodiment, the technique includes implanting at least H+ ions through a front face of a source substrate of silicon carbide with an implantation energy E greater than or equal to 95 keV and an implantation dose D chosen to form an optimal weakened zone near a mean implantation depth, the optimal weakened zone defining the useful layer and a remainder portion of the source substrate. The method also includes bonding the front face of the source substrate to a contact face of the receiving substrate, and detaching the useful layer from the remainder portion of the source substrate along the weakened zone while minimizing or avoiding forming an excess zone of silicon carbide material at the periphery of the useful layer that was not transferred to the receiving substrate during detachment. Such a method facilitates recycling the remainder portion of the source substrate.
Legal claims defining the scope of protection, as filed with the USPTO.
2. The method of claim 1 , wherein the implanted ions comprise H + ions, a combination of H 30 ions and helium ions or a combination of H + ions and boron ions.
3. The method of claim 1 , which further comprises implanting H + ions while maintaining the source substrate at a temperature that is no greater than 200° C.
4. The method of claim 1 , wherein the source substrate comprises a disoriented monocrystalline silicon carbide.
5. The method of claim 1 , which further comprises detaching the useful layer along the optimal weakened zone by applying a thermal budget or mechanical stresses in a manner so that no excess zone remains.
6. The method of claim 5 , wherein the useful layer is detached by applying a thermal budget at a temperature that is greater than about 700° C.
7. The method of claim 1 , which further comprises implanting ions in a random fashion.
8. The method of claim 1 , which further comprises providing a layer of amorphous material on the source substrate before implanting ions, wherein the thickness of the amorphous material is less than or equal to about 50 nanometers.
9. The method of claim 8 , wherein the amorphous material is formed of silicon oxide or silicon nitride.
10. The method of claim 1 , wherein the bonding step comprises molecularly adhering the receiving substrate to the front face of the source substrate.
11. The method of claim 10 , which further comprises providing an intermediate bonding layer on at least one of the front face and the contact face.
12. The method of claim 11 , wherein the intermediate bonding layer comprises an amorphous material.
13. The method of claim 12 , wherein the amorphous material is silicon oxide or silicon nitride.
14. The method of claim 1 , wherein the receiving substrate comprises at least one of silicon, silicon carbide, gallium nitride, aluminum nitride, sapphire, idium phosphide, gallium arsenide, or germanium.
15. The method of claim 1 , wherein the receiving substrate comprises silicon having a low oxygen content.
16. The method of claim 1 , further comprising providing a finished front face of the remainder of the source substrate after detachment for use in subsequent bonding operations.
17. The method of claim 1 wherein the layer is detached by heating the source substrate/receiving substrate assembly to a temperature of above 700° C. until the layer detaches.
18. The method of claim 1 wherein the layer is detached by heating the source substrate/receiving substrate assembly to a temperature of above 800° C. until the layer detaches.
19. The method of claim 1 wherein the layer is detached while minimizing formation of an excess zone of silicon carbide material at the periphery of the useful layer that was not transferred to the receiving substrate during detachment.
20. The method of claim 1 wherein the layer is detached while completely avoiding formation of an excess zone of silicon carbide material at the periphery of the uselful layer that was not transferred to the receiving substrate during detachment.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
July 15, 2004
December 13, 2005
Browse 5M+ US patents with plain-English claim translations and AI-generated analysis.